Re: [PATCH v2 01/11] usb: gadget: add anonymous definition in struct usb_gadget

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Mon, Sep 11, 2023 at 07:24:36PM +0800, Linyu Yuan wrote:
> Some UDC trace event will save usb gadget information, but it will use
> one int size buffer to save one bit information of usb gadget, so more
> than one int buffer to save several bit fields which is not good.
> 
> Add one anonymous union have three u32 members which can be used by trace
> event during fast assign stage to reduce trace buffer usage, and add
> related macro to extract bit fields from u32 members for later trace event
> output state usage.
> 
> Also move sg_supported and other bit fields into one anonymous struct
> which inside anonymous union and Change bit fields from unsigned to u32
> type, it will make sure union member have expected u32 size.
> 
> Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
> ---
> v2: no change
> 
>  include/linux/usb/gadget.h | 63 ++++++++++++++++++++++++++------------
>  1 file changed, 44 insertions(+), 19 deletions(-)
> 
> diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
> index 75bda0783395..cdf62e7f34e7 100644
> --- a/include/linux/usb/gadget.h
> +++ b/include/linux/usb/gadget.h
> @@ -357,6 +357,7 @@ struct usb_gadget_ops {
>   * @in_epnum: last used in ep number
>   * @mA: last set mA value
>   * @otg_caps: OTG capabilities of this gadget.
> + * @dw1: trace event purpose
>   * @sg_supported: true if we can handle scatter-gather
>   * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
>   *	gadget driver must provide a USB OTG descriptor.
> @@ -432,25 +433,49 @@ struct usb_gadget {
>  	unsigned			mA;
>  	struct usb_otg_caps		*otg_caps;
>  
> -	unsigned			sg_supported:1;
> -	unsigned			is_otg:1;
> -	unsigned			is_a_peripheral:1;
> -	unsigned			b_hnp_enable:1;
> -	unsigned			a_hnp_support:1;
> -	unsigned			a_alt_hnp_support:1;
> -	unsigned			hnp_polling_support:1;
> -	unsigned			host_request_flag:1;
> -	unsigned			quirk_ep_out_aligned_size:1;
> -	unsigned			quirk_altset_not_supp:1;
> -	unsigned			quirk_stall_not_supp:1;
> -	unsigned			quirk_zlp_not_supp:1;
> -	unsigned			quirk_avoids_skb_reserve:1;
> -	unsigned			is_selfpowered:1;
> -	unsigned			deactivated:1;
> -	unsigned			connected:1;
> -	unsigned			lpm_capable:1;
> -	unsigned			wakeup_capable:1;
> -	unsigned			wakeup_armed:1;
> +	union {
> +		struct {
> +			u32		sg_supported:1;
> +			u32		is_otg:1;
> +			u32		is_a_peripheral:1;
> +			u32		b_hnp_enable:1;
> +			u32		a_hnp_support:1;
> +			u32		a_alt_hnp_support:1;
> +			u32		hnp_polling_support:1;
> +			u32		host_request_flag:1;
> +			u32		quirk_ep_out_aligned_size:1;
> +			u32		quirk_altset_not_supp:1;
> +			u32		quirk_stall_not_supp:1;
> +			u32		quirk_zlp_not_supp:1;
> +			u32		quirk_avoids_skb_reserve:1;
> +			u32		is_selfpowered:1;
> +			u32		deactivated:1;
> +			u32		connected:1;
> +			u32		lpm_capable:1;
> +			u32		wakeup_capable:1;
> +			u32		wakeup_armed:1;
> +		} __packed;
> +		u32			dw1;
> +#define		USB_GADGET_SG_SUPPORTED(n)			((n) & BIT(0))
> +#define		USB_GADGET_IS_OTG(n)				((n) & BIT(1))
> +#define		USB_GADGET_IS_A_PERIPHERAL(n)			((n) & BIT(2))
> +#define		USB_GADGET_B_HNP_ENABLE(n)			((n) & BIT(3))
> +#define		USB_GADGET_A_HNP_SUPPORT(n)			((n) & BIT(4))
> +#define		USB_GADGET_A_ALT_HNP_SUPPORT(n)			((n) & BIT(5))
> +#define		USB_GADGET_HNP_POLLING_SUPPORT(n)		((n) & BIT(6))
> +#define		USB_GADGET_HOST_REQUEST_FLAG(n)			((n) & BIT(7))
> +#define		USB_GADGET_QUIRK_EP_OUT_ALIGNED_SIZE(n)		((n) & BIT(8))
> +#define		USB_GADGET_QUIRK_ALTSET_NOT_SUPP(n)		((n) & BIT(9))
> +#define		USB_GADGET_QUIRK_STALL_NOT_SUPP(n)		((n) & BIT(10))
> +#define		USB_GADGET_QUIRK_ZLP_NOT_SUPP(n)		((n) & BIT(11))
> +#define		USB_GADGET_QUIRK_AVOIDS_SKB_RESERVE(n)		((n) & BIT(12))
> +#define		USB_GADGET_IS_SELFPOWERED(n)			((n) & BIT(13))
> +#define		USB_GADGET_DEACTIVATED(n)			((n) & BIT(14))
> +#define		USB_GADGET_CONNECTED(n)				((n) & BIT(15))
> +#define		USB_GADGET_LPM_CAPABLE(n)			((n) & BIT(16))
> +#define		USB_GADGET_WAKEUP_CAPABLE(n)			((n) & BIT(17))
> +#define		USB_GADGET_WAKEUP_ARMED(n)			((n) & BIT(18))

Does this actually work on both types of endian-ness?

thanks,

greg k-h